Artificial-tooth crown



(No Model.)

0. M. RICHMOND.

ARTIFICIAL TOOTH GROWN. No. 392,226. Patented Nov. 6, 1888.

: NITEDV STATES PATENT tries.

CASSIUS M. RICHMOND, OF NEW YORK, N. Y., ASSIGNOR 1'0 THE INTER- NATIONAL TOOTH OROWN COMPANY, OF NEW YORK.

ARTIFICIAL-TOOTH CROWN.

SPECIFICATION forming part of Letters Patent No. 392,226, dated November 6, 1888.

(No model.)

To aZZ whom it may concern:

Be it known that I, OASSIUS M. RICHMOND, of the city, county, and State of New York, have invented a new and useful Improvement 5 in Artificial Poreelains, of which the following is a full, true, and exact description, reference being had to the accompanying drawmg.

In the manufacture of artificial dentures IO great difficulty has been experienced from the detaching or breaking away of the artificial poreelains from the supporting gold in the process of mastication. The general method of making such por-eelains has been to bake I5 into the back of the tooth a pin or pins practically parallel with the biting-surface of the tooth, or at right angles to its exterior face or crown. Under those eircu mstances, especially for molar teeth, it is plain that when such teeth are attached by the supporting-pins to a backing of gold a very powerful leverage is exerted,tending to split off the tooth from the backing of gold. In order to prevent this dcstruction, various methods have been employed, among others a method for making the masticating-surface of the tooth of gold, as is exhibited in the patent to A. S. Richmend of .lllfay 22, 1888. In structures of that character, as is apparent, a large amount of gold is necessary in order to secure a proper '1nasticating-surfacc and sufficient strength in the structure. ll'foreover, when the masticatiug-surface of the tooth is made of gold the gold being carried to the face of the tooth 5 is more visible than when such gold does not exist beneath the tooth.

By my improved porcelain I am enabled to dispense with gold. beneath the tooth, and at the same time make a denture which is equally 40 strong or stronger than the previous known dentures, and likewise to effect a large saving in the supporting gold.

My artificial porcelain is applicable to many forms of artificial denture, but is especially .5 useful in that part of the dental art applicable to the construction of bridge-work,where artificial porcelains are carried between the supporting ends of the bridge.

My invention consists in an artificial denture constructed substantially as hereinafter 5c set forth.

A structure embodying my invention is shown in the accompanying sectional drawing, in which A represents the porcelain face or artificial-tooth crown; B, the backing of the 5: gold, and O the supporting-pin.

The invention is illustrated as applied to a molar tooth. The porcelain itself, as will be observed, is much more massive than those usually employed, and its masticating-surface consists of porcelain and not of gold, though it is apparent that the benefits of my invention in a less degree might be obtained even though the masticating-surface were of gold. The pin 0 is baked into thetooth in the usual way in the process of manufacture, and preferably consists ofiridium wire, about No. 16 in size. It is apparent, likewise, that more than one pin could be employed, if desired, though in practice I find one sufficient. The backing B is applied to the back and side of the tooth, as shown, but is apparently much less in mass than has been customarily used in supporting this class of denture, the strength of the porcelain in combination with the pecu- 7 5 liar arrangement of the pin, serving to supply the necessary strength, which was formerly secured only by an increase in the mass of supporting gold. The relation of the pin in the gold prevents both the upward and the lateral 8c movement of the porcelain from the gold, as is apparent, whereas when the pin projects horizontally into the tooth. it cannot prevent the lateral movement of the tooth excepting by the strength of the attachment of the pin within the porcelain, whereas in the structure shown the pin serves as a support independent of the attachment between the pin and the porcelain. The backing is applied in the wellknown way by soldering upon the projecting end of the pin, which should preferably practically project to the inner surface of the back ing to insure the greatest strength.

In this specification I have called the lower part of the gold backingshown at B the lin- 5 gual surface of the denture, and the upper part, B, the palatine surface. In the pre vious art the pins were. connected with the lower part of the backing B, and not with the thefrontthereofat an anglepraeticallyof fortyupper angular surface, B. It is obvious that, five degrees to its vertical axis and united with though I have described the angle of the pin the metallic backing, thereby firmly eonnectr 5 as about forty-five degrees, angles more or ing the parts, substantially as and for the pur- 5 less approaching to this would be useful. pose described.

What I claim as my invention, and desire to In testimony whereofl have signed my name secure by Letters Patent, is to this specification in the presence of two sub- An artificial denture which consists of a scribing witnesses. porcelain facing and a metallic backing con- OASSIUS hL RICHMOND. IO sisting of an angular plate covering the lingual W'itnesses:

and alatine faces of the tooth, and a pin H. UOUTAN'I,

baked into the tooth and extending neerlyto ANTHONY GREF. 

